Historic Typhoon No Match for Chinese Facility

FM Approved standing seam metal roof withstands direct Cat 4 typhoon hit

When Typhoon Mujigae (“rainbow” in Korean) struck southern China’s prosperous Guangdong Province in October, 2015 it was the most powerful tropical cyclone to ever make landfall in that region in recorded history. Thousands of homes and businesses were damaged or destroyed when the Category 4 storm (Figure 1) scored a direct hit on the port city of Zhanjiang with a population of seven million.



While destruction was widespread due to the typhoon’s 135 mph (60 m/s) winds, one nondescript brick building in one of the city’s many industrial zones stood out from its damaged neighbors for one important reason: it survived the storm virtually intact.


Local loss prevention advice and certified products

This multi-level brick facility consists of a single-story production area and three-story office section, with an FM Approved roof system (Figure 2) on the structure. “However, the initial design for our building called for a roof that followed only the local code,” notes one of the facility’s managers. “We are located in a coastal city and it is normal for us to experience typhoons.”




Building envelope integrity is critically important for every business, and even a small breach could mean major downtime. According to the risk consultant who worked with the facility’s design team, “Metal roofs are a popular option for many industrial facilities in China. It is highly likely that their building would have been damaged by this typhoon had they not gone with an FM Approved roof. Many buildings all around them were severely damaged by the storm, including roofs peeled off and walls destroyed.”


The facility design team chose a locally produced FM Approved roof and followed the installation guidelines from FM Global Property Loss Prevention Data Sheet 1-28 (Wind Design). “At the time of this project, this was the first exposure to FM Approved roofing for us and our contractor,” the facility manager noted.


FM Approvals China manager Bessie Wong says, “We have worked hard over the past 10 years to build local awareness of FM Approvals and to develop the availability of Approved products throughout China. Initially, foreign manufacturers were the first to produce FM Approved roof and wall systems in China, but now the mix of foreign and indigenous producers is about half and half. We have been helped by the adoption of certain FM Approvals roof and wall standards into the Chinese national building code and the local availability of our wind uplift testing for roof systems.”


Shanghai firm provides FM Approved roof system

The manufacturer chose an FM Approved roof system from Shanghai Beststeel Steel Structure Building Co. Ltd (Beststeel). The firm is an indigenous Chinese producer of steel structures and cladding systems, including prefabricated roofs and wall systems, as well as steel decking systems and other products.


Beststeel was granted its first FM Approved certification in 2008 for its SS-468 standing seam metal roof system, the same one chosen for the Zhanjiang facility. Following certification, the Beststeel roofing system was listed in FM Approvals’ RoofNav Web-based system for the planning, specification and selection of FM Approved roof assemblies. (www.RoofNav.com)


According to Beststeel founder and chairman Jinyong Xu, the 20-year-old firm was not surprised to be asked to provide a bid for an FM Approved roof for a project in Zhanjiang City. “Zhanjiang is located in one of the highest wind load areas of China. FM Global engineers provided us with the structural requirements for that area, including wind and precipitation. We worked with the local roofing contractor and provided on-site guidance to ensure installation quality.”


Beststeel has also provided FM Approved roof systems for two other projects in Zhanjiang. One of the projects, an auto parts manufacturing facility, was completed before Typhoon Mujigae struck, and it weathered the storm with no damage. The other, a beverage bottling plant (Figure 3) was not so lucky. Its original roof, built to local codes but not FM Approved, was peeled off by Mujigae. The bottler elected to replace it with a Beststeel FM Approved roof.



Xu noted that customers recognize the value in choosing a certified roof system. “The FM Approved mark is a symbol of the highest quality in the minds of our customers. Particularly in coastal areas, customers are choosing our FM Approved roofs and wall systems not only for their wind performance, but for their proven fire resistance and other factors as well. The contrast between the performance of a certified roof and one that meets only local codes is especially obvious following severe wind events such as Mujigae.”


“Our investment in a roof engineered for our wind environment paid off in just a few years,” the facility manager emphasizes. “Since last year, our facility and our FM Approved roof has been a model project for many in this region. Others are learning from our example.”